Abstract: A method for estimating a signal charge collected by a pixel of an image sensor includes determining an average bias that depends on the pixel's floating-diffusion dark current and pixel-sampling period. The method also includes determining a signal-charge estimate as the average bias subtracted from a difference between a weighted sum of a plurality of N multiple-sampling values each multiplied by a respective one of a plurality of N sample-weights.

Abstract: In some embodiments, an imaging system is provided. The imaging system comprises an image sensor, a light source, control circuitry, and function logic. The image sensor comprises a pixel array that includes a plurality of polarization pixel cells and a plurality of time-of-flight pixel cells. The light source is configured to emit light pulses to an object. The control circuitry is coupled to the light source and the pixel array, and is configured to synchronize a timing of the emission of the light pulses with sensing of photons reflected from the object by the plurality of time-of-flight pixel cells to generate depth information. The function logic is configured to determine a set of ambiguous surface normals using signals generated by the plurality of polarization pixel cells, and to disambiguate the set of ambiguous surface normals using the depth information to generate a three-dimensional shape image.

Abstract: A method for estimating a signal charge collected by a pixel of an image sensor includes determining an average bias that depends on the pixel's floating-diffusion dark current and pixel-sampling period. The method also includes determining a signal-charge estimate as the average bias subtracted from a difference between a weighted sum of a plurality of N multiple-sampling values each multiplied by a respective one of a plurality of N sample-weights.

Abstract: An imaging system including an image sensor coupled to a controller to image an external scene is described. The controller includes logic storing instructions that when executed causes the imaging system to perform operations including capturing images, including a first image and a second image, of an external scene, and generating reduced representations of the images including a first reduced representation associated with the first image and a second reduced representation associated with the second image. The operations further include comparing the first reduced representation with the second reduced representation to determine a difference between the first image and the second image and identifying an occurrence of an occlusion affecting the image sensor imaging the external scene when the difference is greater than a threshold value.

Abstract: An optical system comprises an imaging lens for imaging an object to an image and a sensing pixel array for detecting lights from the object toward the image. The sensing pixel array comprises a first sensing pixel and a second sensing pixel, each sensing pixel comprising a microlens covering a one-dimensional series of photodiodes having n photodiodes. A photodiode at an end of the one-dimensional series of photodiodes of the first sensing pixel detects a first light from the object toward the image, and a photodiode at an opposite end of the one-dimensional series of photodiodes of the second sensing pixel detects a second light from the object toward the image, where the first light and the second light pass opposite parts of the imaging lens.

Abstract: A method and apparatus for embedding a digital watermark in image content that is not visible to the human eye is performed on single-sensor digital camera images (often called ‘raw’ images) from a pixel-array. The raw image is transformed to generate preprocessed image coefficients, a watermark message is encrypted using a first key; the encrypted watermark message is randomized using a second key to form a watermark; and the watermark is embedded in randomly selected preprocessed image coefficients.

Abstract: An autofocusing method includes capturing an image of a scene with a camera that includes a pixel array; computing a horizontal-difference image, and a vertical-difference image; and combining the horizontal-difference image and the vertical-difference image to yield a combined image. The method also includes determining, from the combined image and the intensity image, an image distance with respect to a lens of the camera at which the camera forms an in-focus image. The pixel array includes horizontally-adjacent pixel pairs and vertically-adjacent pixel pairs each located beneath a respective microlens. The horizontal-difference image includes, for each horizontally-adjacent pixel pair, a derived pixel value that is an increasing function of a difference between pixel values generated by the horizontally-adjacent pixel pair.

Abstract: A sample and hold (SH) circuit includes a pixel level connection coupled to a pixel cell. A reset row transistor is coupled between a first supply voltage and the pixel level connection. A source follower row transistor having a gate is coupled to the pixel level connection. A row select row transistor is coupled between the source follower row transistor and a bitline. A first storage transistor is coupled to the pixel level connection. A first storage device is coupled between the first storage transistor and a second supply voltage. A second storage transistor is coupled to the pixel level connection. A second storage device is coupled between the second storage transistor and the second supply voltage.

Abstract: A sensor includes a photodiode disposed in a semiconductor material to receive light and convert the light into charge, and a first floating diffusion coupled to the photodiode to receive the charge. A second floating diffusion is coupled to the photodiode to receive the charge, and a first transfer transistor is coupled to transfer the charge from the photodiode into the first floating diffusion. A second transfer transistor is coupled to transfer the charge from the photodiode into the second floating diffusion, and an inductor is coupled between a first gate terminal of the first transfer transistor and a second gate terminal of the second transfer transistor. The inductor, the first gate terminal, and the second gate terminal form a resonant circuit.

Abstract: In some embodiments, an imaging system is provided. The imaging system comprises an image sensor, a light source, control circuitry, and function logic. The image sensor comprises a pixel array that includes a plurality of polarization pixel cells and a plurality of time-of-flight pixel cells. The light source is configured to emit light pulses to an object. The control circuitry is coupled to the light source and the pixel array, and is configured to synchronize a timing of the emission of the light pulses with sensing of photons reflected from the object by the plurality of time-of-flight pixel cells to generate depth information. The function logic is configured to determine a set of ambiguous surface normals using signals generated by the plurality of polarization pixel cells, and to disambiguate the set of ambiguous surface normals using the depth information to generate a three-dimensional shape image.

Abstract: An optical system comprises an imaging lens for imaging an object to an image and a sensing pixel array for detecting lights from the object toward the image. The sensing pixel array comprises a first sensing pixel and a second sensing pixel, each sensing pixel comprising a microlens covering a one-dimensional series of photodiodes having n photodiodes. A photodiode at an end of the one-dimensional series of photodiodes of the first sensing pixel detects a first light from the object toward the image, and a photodiode at an opposite end of the one-dimensional series of photodiodes of the second sensing pixel detects a second light from the object toward the image, where the first light and the second light pass opposite parts of the imaging lens.

Abstract: A sensor includes a photodiode disposed in a semiconductor material to receive light and convert the light into charge, and a first floating diffusion coupled to the photodiode to receive the charge. A second floating diffusion is coupled to the photodiode to receive the charge, and a first transfer transistor is coupled to transfer the charge from the photodiode into the first floating diffusion. A second transfer transistor is coupled to transfer the charge from the photodiode into the second floating diffusion, and an inductor is coupled between a first gate terminal of the first transfer transistor and a second gate terminal of the second transfer transistor. The inductor, the first gate terminal, and the second gate terminal form a resonant circuit.

Abstract: An imaging array and method for fabricating the same are disclosed. The imaging array includes a semiconductor substrate having a plurality of VIS pixel sensors and a plurality of SWIR readout circuits fabricated therein. An insulating layer is deposited on the semiconductor substrate. The insulating array has wells overlying the SWIR pixel sensors. A plurality of SWIR photodiodes are deposited in the wells. Each SWIR photodiode is located in a corresponding one of the wells and is connected by an electrically conducting path with the SWIR readout circuit underlying the SWIR photodiode. An electrically conducting transparent electrode overlying the SWIR photodiodes is connected to each of the SWIR photodiodes.

Abstract: An x-ray imaging system and a method for retrofitting existing x-ray generators to allow those generators to be controlled by a digital x-ray imaging system are disclosed. The x-ray imaging system includes an imaging array and an image controller. The imaging array is configured to be positioned within a patient's mouth, the imaging array acquiring an image of the patient's teeth when the patient's head is illuminated with x-rays. The imaging array includes an x-ray dosimeter that provides an x-ray exposure signal indicative of an x-ray exposure received by the imaging array. The image controller is coupled to the imaging array and receives the x-ray exposure signal, the image controller includes a first wireless link that controls an x-ray generator by initiating a pre-programmed x-ray exposure. The wireless controllable switch can be used to replace an existing manually controlled switch in an existing x-ray generator.

Abstract: A pixel sensor having a main photodiode and a parasitic photodiode and a method for reading out that pixel sensor are disclosed. The parasitic photodiode also serves the function of a floating diffusion node in the pixel. The pixel sensor is read by first determining the exposure as measured by the parasitic photodiode and then determining the exposure as read by the main photodiode. One of the two exposure measurements is chosen as the pixel output. The main photodiode has a light conversation efficiency chosen such that one of the two measurements will provide a measurement of the exposure over a dynamic range that is greater than that of either the main photodiode or the parasitic photodiode utilized separately.

Abstract: A pixel sensor having a main photodetector and a parasitic photodiode and a method for reading out that pixel sensor are disclosed. The pixel sensor is read by reading a first potential on a floating diffusion node in the pixel sensor while the floating diffusion node is isolated from the main photodiode. The pixel sensor is then exposed to light such that the floating diffusion node and the photodetector are both exposed to the light. A second potential on the floating diffusion node is then readout while the floating diffusion node is isolated from the main photodiode. After the first and second potentials are readout, a third potential on the floating diffusion node is readout. The main photodiode is then connected to the floating diffusion node, and a fourth potential on the floating diffusion node is readout. First and second light intensities are determined from the readout potentials.

Abstract: An imaging array and method for fabricating the same are disclosed. The imaging array includes a semiconductor substrate having a plurality of VIS pixel sensors and a plurality of SWIR readout circuits fabricated therein. An insulating layer is deposited on the semiconductor substrate. The insulating array has wells overlying the SWIR pixel sensors. A plurality of SWIR photodiodes are deposited in the wells. Each SWIR photodiode is located in a corresponding one of the wells and is connected by an electrically conducting path with the SWIR readout circuit underlying the SWIR photodiode. An electrically conducting transparent electrode overlying the SWIR photodiodes is connected to each of the SWIR photodiodes.

Abstract: An image sensor is described having a pixel array. The pixel array has a unit cell that includes visible light photodiodes and an infra-red photodiode. The visible light photodiodes and the infra-red photodiode are coupled to a particular column of the pixel array. The unit cell has a first capacitor coupled to the visible light photodiodes to store charge from each of the visible-light photodiodes. The unit cell has a readout circuit to provide the first capacitor's voltage on the particular column. The unit cell has a second capacitor that is coupled to the infra-red photodiode through a first transfer gate transistor to receive charge from the infra-red photodiode during a time-of-flight exposure. The first capacitor is coupled to the infra-red photodiode through a second transfer gate transistor to receive charge from the infra-red photodiode during the time-of-flight exposure.

Abstract: An image sensor is described having a pixel cell unit. The pixel cell unit has first, second and third transfer gate transistor gates on a semiconductor surface respectively coupled between first, second and third visible light photodiode regions and a first capacitance region. The pixel cell unit has a fourth transfer gate transistor gate on the semiconductor surface coupled between a first infrared photodiode region and a second capacitance region.

Abstract: An x-ray imaging system and a method for retrofitting existing x-ray generators to allow those generators to be controlled by a digital x-ray imaging system are disclosed. The x-ray imaging system includes an imaging array and an image controller. The imaging array is configured to be positioned within a patient's mouth, the imaging array acquiring an image of the patient's teeth when the patient's head is illuminated with x-rays. The imaging array includes an x-ray dosimeter that provides an x-ray exposure signal indicative of an x-ray exposure received by the imaging array. The image controller is coupled to the imaging array and receives the x-ray exposure signal, the image controller includes a first wireless link that controls an x-ray generator by initiating a pre-programmed x-ray exposure. The wireless controllable switch can be used to replace an existing manually controlled switch in an existing x-ray generator.